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<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<script>
		var num  = 100;

		function run(num) {//形参
			tt = 200;
			alert(num);
			// alert(yy1);
		}

		// run(10);//实参

		// alert(tt);

		num = 0;

		function a() {
			num++;
		}

		for (var i = 1; i <100; i++) {
			if(i%3==0){
				a();
			}
		}

		document.write(num);
	</script>
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<body>
	
</body>
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